You actually did not see much of the actual spankings as he would usually be sitting at his desk which would hide most of the recipient. All you usually saw was a face poking out around the side of the desk which could be either smiling, red with embarrassment or grimacing with pain.
Boys and very occasionally girls would sometimes be sent to him with a note from other teachers to get a whacking . In these instances our lesson would be temporarily disrupted while he dealt with the errant pupil. In these cases he usually whacked quite hard.
He also had a cane but he rarely used it in class sometimes giving boys 2 on each hand for things like bullying and stealing. I don’t think he ever caned a girl or threatened to do so.